Geom collision

Game Mechanics
#1

Hello,

I want to create an application which tests the collision of geoms (not bodies). When i run the following program, i get contact counts as zero. Do you have any idea about what the problem is?

(In fact i want to test collision of trimeshes but this simple example just test collision of a sphere and a box)


public class TestBoxSphereGeomCollision {

   World world;
   HashSpace space;
   JavaCollision collision;
   Contact contact;

   GeomBox box;
   GeomSphere sphere;

   public TestBoxSphereGeomCollision() {
        
        Odejava.getInstance();
        initWorld();
        initObjects();
        
        for (int i=0; i<100; i++) {
            step();
        }
        
        cleanup();
   }

    private void initWorld() {    
        world = new World();
        world.setGravity(0f, 0f, 0f);
        world.setStepInteractions(10);
        world.setStepSize(0.05f);
        
        collision = new JavaCollision(world);

        contact =
                new Contact(
                collision.getContactIntBuffer(),
                collision.getContactFloatBuffer());
        
        space = new HashSpace();
        
        collision.setSurfaceMode(0);
        collision.setSurfaceMu(Float.MAX_VALUE);
    }

    private void initObjects() {

        box = new GeomBox("box1", 15, 15, 15);
        box.setPosition(0f , 0f, 0f);        
        
        space.addGeom(box);
        
        sphere = new GeomSphere("sphere1",  20);
        sphere.setPosition(0f , 0f, 1f);        
        space.addGeom(sphere);
    }

    public void step() {
    
        //collision.collide(space);
        collision.collide2(box.getNativeAddr(), sphere.getNativeAddr());
       // Note that i tried both versions of colliding written above

        iterateContacts();
        collision.applyContacts();
        
        world.stepFast();
    }    

    private void iterateContacts() {
        
        System.out.println("ContactCount: "+collision.getContactCount());

    }

    public void cleanup() {
        space.delete();
        collision.delete();
        world.delete();
        Ode.dCloseODE();
    }
}
#2

IIRC, it’s possible that static geom collision has been disabled in the code. For some environments this is desired. If this is the case, we should make it a flag.

Will.

#3

Hmm, didn’t you answer your own question in this thread?

I thought I remembered reading something about it :slight_smile:

Will.

#4

Yes. You are right.

In fact i was going to post the url here before, but i could not login to the forum :frowning: So, i creted another account now.

Thanks.